The Child and Family Research Section (CFRS) in the Laboratory of Comparative Ethology in the National Institute of Child Health and Human Development investigates dispositional, experiential, and environmental factors that contribute to physical, mental, emotional, and social development in human beings during the first two decades of life. The research goals of the CFRS are to describe, analyze, and assess (a) the capabilities and proclivities of developing children, including their physiological functioning, perceptual and cognitive abilities, emotional and social growth, and interactional styles; (b) the nature and consequences of interactions within the family and the social world for children and parents; and (c) influences on development of children's exposure to and interactions with the natural and designed environment. Research topics concern the origins, status, and development of diverse psychological constructs, structures, functions, and processes in the first two decades of life; effects of child characteristics and activities on parents; and the meaning of variations in parenting and in the family across different sociodemographic and cultural groups. Laboratory and home-based studies employ a variety of approaches, including psychophysiological recordings, experimental techniques, behavioral observations, standardized assessments, rating scales, interviews, and demographic/census records in both longitudinal and cross-sectional designs. Sociodemographic comparisons under investigation include family SES, maternal age and employment status, and child parity and daycare experience. Cultural study sites include Argentina, Australia, Belgium, Brazil, Cameroon, Canada, Chile, England, France, Israel, Italy, Japan, Kenya, Peru, the Republic of South Korea, as well as the United States; in all places, intra-cultural as well as cross-cultural comparisons are pursued. The Child and Family Research Section was established with the broad aim of initiating an investigative program on the ways in which development is affected by variations in the conditions under which human beings are reared. The CFRS also conducts a broad program of research in neuroscience and behavioral pediatrics that investigates questions at the interface of child development, biology, and health. Childhood is a time of vulnerability (to accidents, in risk taking), as it is formative in habit development and decision making (nutrition, exercise) for the balance of the life span. This research has several facets, including fetal growth and development and their predictive validity for postnatal performance, the role of vagal function in psychological development, development and function following preterm birth, the impact of deafness on child development and family life, development after in utero cocaine exposure, the developmental sequelae of cancer and surgery in infancy, children's knowledge, implementation, and evaluation of strategies for coping with stressful medical interventions, and effects of maternal depression on child development and parenting. To meet this multifaceted charge, the CFRS has undertaken three integrated multicultural, multivariate, multiage research programs that are supplemented by a variety of ancillary investigations. These research programs represent an en bloc effort. The first program is a prospective longitudinal study designed to explore multiple aspects of child development in the context of major sociodemographic comparisons. The second program broadens the perspectives of the first to encompass cultural influences on development within the same basic longitudinal framework. The third program is composed of applied extensions of this basic research into neuroscience and behavioral pediatrics. The ultimate aims of these research programs are concerned directly with promoting aware, fit, and motivated children who, as a hopeful eventuality, willl grow into knowledgeable, healthy, and happy adults.